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Posterior Limb (posterior + limb)
Selected AbstractsAnterior to posterior limb of the internal capsule morphology in fragile X syndromeDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2009Cherine Fahim PhD No abstract is available for this article. [source] Quantitative T1 mapping of hepatic encephalopathy using magnetic resonance imagingHEPATOLOGY, Issue 5 2003Nadim Joni Shah M.D. Changes are shown in the spin-lattice (T1) relaxation time caused by the putative deposition of manganese in various brain regions of hepatic encephalopathy (HE) patients using a novel and fast magnetic resonance imaging (MRI) method for quantitative relaxation time mapping. A new method, T1 mapping with partial inversion recovery (TAPIR), was used to obtain a series of T1 -weighted images to produce T1 maps. Imaging of 15 control subjects and 11 patients was performed on a 1.5T MRI scanner. The measurement time per patient with this technique, including adjustments, was ,5 minutes. Regions of interest in the globus pallidus, the caudate nucleus, the posterior and anterior limbs of the internal capsule, the putamen, the frontal and occipital white matter, the white matter of the corona radiata, the occipital visual and frontal cortices, and the thalamus were interactively defined in the left hemisphere and analyzed with respect to their T1 values. T1 changes in the brains of HE patients can be determined quantitatively with TAPIR in short, clinically relevant measurement times. Significant correlations between the change in T1 and HE severity have been shown in the globus pallidus, the caudate nucleus, and the posterior limb of the internal capsule. No significant correlation of T1 with grade of HE was found in the putamen, frontal white matter, white matter of the corona radiata, white matter in the occipital lobe, the anterior limb of the internal capsule, visual cortex, thalamus, or frontal cortex. In conclusion, these measurements show that T1 mapping is feasible in short, clinically relevant acquisition times. [source] Neuroimaging predictors for depressive symptoms in cerebral small vessel diseaseINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2010Jian Hui Fu Abstract Objective Although cerebral small vessel disease (SVD) is closely associated with late life depression, patients with even severe SVD may have no depressive symptoms. We postulate that concurrent brain atrophy may also involve in the pathogenesis of depressive symptoms in SVD. We aimed to investigate the relevance of brain atrophy in predicting depressive symptoms among patients with severe SVD. Methods We recruited 45 lacunar stroke patients who had diffuse white matter lesion (WML) and varying severity levels of depressive symptoms. We used a quantitative hybrid warping method to determine the volume of 99 brain regions for each patient. We assessed severity of depressive symptoms using the depression score of the hospital anxiety and depression scale (HADS-D). We first performed correlation analysis of each brain variable with the depression score. Significant variables were then entered separately into linear regression analysis to explore predictors of HADS-D, with adjustment of relevant clinical variables. Results The mean age (SD) of the 45 participants was 74.6 (8.3) years. The mean HADS-D score was 3.5, with score ranging from 0 to15. Variables that had a significant correlation coefficient with HADS-D were gender, hypertension, Oxford handicap scale, left inferior frontal gyrus, right subthalamic nucleus, left posterior limb of internal capsule, and right cerebellum. Regression analyses showed that only left inferior frontal gyrus atrophy (,,=,,0.354, p,=,0.017) predicted HADS-D score after adjusted for other relevant clinical variables. Conclusion Concurrent atrophy of left inferior frontal gyrus is associated with depressive symptoms in elderly patients with severe SVD. Copyright © 2009 John Wiley & Sons, Ltd. [source] Retrograde Wallerian degeneration of cranial corticospinal tracts in cervical spinal cord injury patients using diffusion tensor imagingJOURNAL OF NEUROSCIENCE RESEARCH, Issue 10 2008Saurabh Guleria Abstract Diffusion tensor imaging (DTI) has the potential to reveal disruption of white matter microstructure in chronically injured spinal cords. We quantified fractional anisotropy (FA) and mean diffusivity (MD) to demonstrate retrograde Wallerian degeneration (WD) of cranial corticospinal tract (CST) in cervical spinal cord injury (SCI). Twenty-two patients with complete cervical SCI in the chronic stage were studied with DTI along with 13 healthy controls. Mean FA and MD values were computed for midbrain, pons, medulla, posterior limb of internal capsule, and corona radiata. Significant reduction in the mean FA and increase in MD was observed in the cranial CST in patients with SCI compared with controls, suggesting retrograde WD. Statistically significant inverse FA and MD changes were noted in corona radiata, indicating some restoration of spared white matter tracts. Temporal changes in the DTI metrics suggest progressing degeneration in different regions of CST. These spatiotemporal changes in DTI metrics suggest continued WD in injured fibers along with simultaneous reorganization of spared white matter fibers, which may contribute to changing neurological status in chronic SCI patients. © 2008 Wiley-Liss, Inc. [source] Neurokinin B-producing projection neurons in the lateral stripe of the striatum and cell clusters of the accumbens nucleus in the ratTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 2 2004Ligang Zhou Abstract Neurons producing preprotachykinin B (PPTB), the precursor of neurokinin B, constitute 5% of neurons in the dorsal striatum and project to the substantia innominata (SI) selectively. In the ventral striatum, PPTB-producing neurons are collected mainly in the lateral stripe of the striatum (LSS) and cell clusters of the accumbens nucleus (Acb). In the present study, we first examined the distribution of PPTB-immunoreactive neurons in rat ventral striatum and found that a large part of the PPTB-immunoreactive cell clusters was continuous to the LSS, but a smaller part was not. Thus, we divided the PPTB-immunoreactive cell clusters into the LSS-associated and non-LSS-associated ones. We next investigated the projection targets of the PPTB-producing ventral striatal neurons by combining immunofluorescence labeling and retrograde tracing. After injection of Fluoro-Gold into the basal component of the SI (SIb) and medial part of the interstitial nucleus of posterior limb of the anterior commissure, many PPTB-immunoreactive neurons were retrogradely labeled in the LSS-associated cell clusters and LSS, respectively. When the injection site included the ventral part of the sublenticular component of the SI(SIsl), retrogradely labeled neurons showed PPTB-immunoreactivity frequently in non-LSS-associated cell clusters. Furthermore, these PPTB-immunoreactive projections were confirmed by the double-fluorescence method after anterograde tracer injection into the ventral striatum containing the cell clusters. Since the dorsalmost part of the SIsl is known to receive strong inputs from PPTB-producing dorsal striatal neurons, the present results indicate that PPTB-producing ventral striatal neurons project to basal forebrain target regions in parallel with dorsal striatal neurons without significant convergence. J. Comp. Neurol. 480:143,161, 2004. © 2004 Wiley-Liss, Inc. [source] Early prediction of aphasia outcome in left basal ganglia hemorrhageACTA NEUROLOGICA SCANDINAVICA, Issue 3 2001C.-L. Liang Objectives , The independent predictors of aphasia outcome for patients with left basal ganglia hemorrhage were evaluated. Patients and methods, We included 140 patients of 1036 patients with spontaneous intracerebral hemorrhage admitted to our hospital from January 1993 through December 1997. Aphasia was assessed using the aphasia scale of the Scandinavian stroke scale. Univariate and step-wise logistic regression analyses were performed to assess the relationships between the initial aphasia score, age, gender, blood volume, locations of hematoma and aphasia outcome. Results, Step-wise logistic regression analysis revealed that the following two factors were independently associated with the final aphasia outcome: initial aphasia score (P<0.0001) and location of hematoma involving the posterior limb of the internal capsule (P=0.004). Conclusions, A particularly high likelihood of poor aphasia outcomes of patients with left basal ganglia hemorrhage are predicted in those who have poor initial aphasia score and whose brain computed tomography shows the hematoma involves the posterior limb of the internal capsule. [source] Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum DisorderALCOHOLISM, Issue 2 2010Catherine Lebel Background:, Children with fetal alcohol spectrum disorder (FASD) often demonstrate a variety of cognitive deficits, but mathematical ability seems to be particularly affected by prenatal alcohol exposure. Parietal brain regions have been implicated in both functional and structural studies of mathematical ability in healthy individuals, but little is known about the brain structure underlying mathematical deficits in children with FASD. The goal of this study was to use diffusion tensor imaging (DTI) to investigate the relationship between mathematical skill and brain white matter structure in children with FASD. Methods:, Twenty-one children aged 5 to 13 years diagnosed with FASD underwent DTI on a 1.5-T MRI scanner and cognitive assessments including the Woodcock-Johnson Quantitative Concepts test. Voxel-based analysis was conducted by normalizing subject images to a template and correlating fractional anisotropy (FA) values across the brain white matter with age-standardized math scores. Results:, Voxel-based analysis revealed 4 clusters with significant correlations between FA and math scores: 2 positively-correlated clusters in the left parietal region, 1 positively-correlated cluster in the left cerebellum, and 1 negatively-correlated cluster in the bilateral brainstem. Diffusion tractography identified the specific white matter tracts passing through these clusters, namely the left superior longitudinal fasciculus, left corticospinal tract and body of the corpus callosum, middle cerebellar peduncle, and bilateral projection fibers including the anterior and posterior limbs of the internal capsule. Conclusions:, These results identify 4 key regions related to mathematical ability and provide a link between brain microstructure and cognitive skills in children with FASD. Given previous findings in typically developing children and those with other abnormal conditions, our results highlight the consistent importance of the left parietal area for mathematical tasks across various populations, and also demonstrate other regions that may be specific to mathematical processing in children with FASD. [source] | |||||||||||||